


fill

by Red



Category: X-Men: First Class (2011) - Fandom
Genre: Alpha Erik, Alpha/Beta/Omega Dynamics, Alpha/Omega, Breeding, Breeding Cycle, Charles Getting Uncomfortable, Don't Examine This Too Closely, Dubious Consent, Impregnation, M/M, Mating Cycles/In Heat, Omega Charles, Sexual Violence, X-Men First Class Kink Meme
Language: English
Status: Completed
Published: 2011-12-14
Updated: 2011-12-14
Packaged: 2017-12-07 21:12:11
Rating: Explicit
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 15,769
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/753125
Author URL: https://archiveofourown.org/users/Red/pseuds/Red
Summary: <blockquote class="userstuff">
              <p>Or, "Untitled Mating Fic: Finally Edited and Still Rather Embarrassing for Everyone Involved." </p>
<p>Charles is an omega who's accustomed to spending heats alone, sweating it out and ignoring his biology. But after meeting Erik and being more-or-less confined to the CIA compound, he finds himself unable to resist the lure of giving in to his hormones.</p>
<p>So, the mating thing happens in detail, and that's pretty much the fic. As warning: this is pretty sketchily consensual, in the way many breeding fics can be, but somehow seems EXTRA so by the end of the story. Please be careful of any triggers, as far as that goes.</p>
            </blockquote>





	fill

**Author's Note:**

> Thank you to subluxate for editing. Any remaining issues are all me! 
> 
> Originally, I wrote this as a sort of "comment box" fill on 1stclass_kink. It took me ages to edit it and upload it on AO3, but the original prompt [can be found here](http://1stclass-kink.livejournal.com/6527.html?thread=10502271#t10502271).

Not now. 

Any time, any place else would be better than here, now, and what Charles wouldn't give to have listened to Raven and let her set up a prearranged mate years ago. It was the thing families were supposed to do for his type, but his family had always been distant at best. And every year since puberty, he'd been able to manage this easily on his own. A few telepathic nudges of "shove off, I'm mated" to the handful of alpha males he passed in the halls, a week holed up alone in his rooms with Raven for company. 

The cycles could at least have the grace to be consistent. He'd never gone into heat in summer before. 

He'd never gone into heat in a sodding CIA complex, packed wall-to-wall with alphas--including three mutant alphas--before, either, and here he was, sitting in a bathroom trembling. The first signs of heat were subtle: the way his skin itched for touch, the way he instinctively began to respond to the sharp hypnotic scent (usually undetectable) of alpha males, the slow awakening of dormant glands. By now, however, he felt constantly open, soft and slick. He walked by the alphas--so many, he despaired of tricking them all with his halfhearted attempts to thwart mating--and couldn't help trying to display himself. 

Which is what led to this--some agent assigned to them, catching his arousal, putting hands roughly on Charles' hips; Charles resisting, sending desperately _no, I'm mated, for god's sake_ , but the agent was mad from the pheromones; the sudden jerk of the man being forcibly removed, crying out as he was pulled by a watch, a belt, a gun. When Erik stood before him, asking if Charles was injured, he still held the agent with his powers. 

_He would kill for me_ , Charles thought as he muttered a quick assurance to Erik, backing away, _he would kill for his mate_. He wanted to strip right there, the undignified need to be bred never stronger. Erik smelled of health, vicious determination, the subtle difference of mutant genes calling out to him. 

Instead, Charles retreated. Evolutionary drives were things to be studied, he reminded himself, not to be controlled by. There were also far better mates out there than Erik, who would likely run off the minute he'd knocked Charles up. 

But even when he finally emerged hours later to return to his room, his legs were shaking, and he kept seeing it in his mind: _Erik, flushed from fighting off a facility full of alphas; Erik, thrusting ruthlessly, filling Charles over and over with his seed._

The phenomenon of heat was still poorly understood by modern science. Charles himself had found more questions than answers in his own studies on the matter. Why did it occur in 48% of the overall population? Why did it cross the apparent boundary of sex differentiation? What was the evolutionary advantage? Why did cycles only occur once a year--and unpredictably? 

Were cycles influenced by surroundings? Because, if so, Charles was currently rather furious that he was the only person in heat in the entire complex.

What he did know was that heat lasted, on average, five to six days. That impregnation--in males or females--was only possible in this brief period. That pheromones were released at an accelerated, exponential rate as the heat progressed, driving other omegas to crowd around in an instinct to protect and assist in the inevitable need to settle and nest following impregnation, and driving alphas to do anything to ensure their genes were the ones chosen to survive. 

Charles was approximately one and a half days into his heat, and he was going to kill Hank. 

"I'm fine Hank," he said, for the fifth time that day. "I'm in heat, not dying." Hank kept trying to get him to sit down, to relax and eat more, and there was no way to logically explain that _no, I don't need the extra energy because I will not be mating, thank you._

Sitting also just wasn't advisable, what with all the alphas sniffing around. 

At least here, he imagined, it was safe. Within the safe house portion of the facility, there was less of a threat from unmated males. Sean and Darwin were naturally somewhat agitated, but two young alphas wouldn't pose too much of a problem. 

Of course, convincing Erik of this was a bit more... difficult.

It never failed. If Sean entered the room, not five minutes later, there Erik would be. If Darwin stopped him to talk on the grounds--he was still attempting to use Cerebro, much as Hank would awkwardly fumble through euphemisms to voice his thoughts of _wouldn't you rather be, well, um_ \--Erik would find an excuse to stalk by. It was all rather excessive, Charles thought.

Extremely excessive, Sean apparently thought, as he and Alex came in. Sean had been pointedly ignoring Charles, his thoughts a murmur of _he's just a dork, not good looking at all, just keep cool_ when Erik predictably appeared, his sharp smile all threat and Sean finally had enough. 

If the mental grocery list of Reasons Charles Xavier Is Not Attractive wasn't reason enough to slink away in mortification (Sean was well up to item 294), the sudden outburst of "Jesus, I'm not stupid. I won't steal your mate," just about did it. 

"Sean--" he began, meaning to correct Sean. He was no one's mate, he wasn't about to be owned and bred like some animal. But the sharp spike of something like vicious pride from Erik made him stop, awkwardly. 

"Why don't you guys just stay in your room for the week," Sean added, helpfully. "Instead of trying to kill me." 

Maybe it was just because he wasn't in his right mind--usually he knew exactly what to say, usually he could read, in an instant, the proper thing to say to appease--but all he could do was feel the weight of Erik's possessiveness and stammer an excuse about fresh air and leave. 

Demeaning as it was, he supposed it was lucky that omegas in heat were expected to be irrational.

 

Taking in the night air was, he realizes quickly, a wise decision. There were less thoughts crowding him, for one. Though he was used to living with his mind brushing constantly against others, he'd always had a particular difficulty shielding himself during heat, and he'd always taken to hiding in his room during the last days of his cycle. Perhaps Hank was right. Perhaps he was pushing himself too much, continuing the search for mutants.

Perhaps Sean was right, his mind traitorously supplied. Perhaps he should just stay locked in a room, alone with nothing but Erik and a mattress and sheets damp with sweat and cum--

Bracing, he thought, shaking himself. That's what the air was supposed to be. Bracing against the impossible wave of arousal growing within him, the way he feels ill with it. Although there are several cases of omegas who never mate, research shows non-mating omegas experience increasingly debilitating heat cycles each year, he recalls. It's not as if he'll die if he doesn't get fucked, he knows that logically.

But it doesn't stop this from _feeling_ terminal.

"'Mutant and proud,' and you can't even cope with being an omega."

He was caught up enough in his own thoughts--and her thoughts were familiar enough to him to pass by, at times, unnoticed--that Raven's words startle him. 

She's standing, arms folded, leaning against the building. She's wearing her own face, and she's got the expression she's had every time he's gone to lock himself alone in a room with his hormones: all near-parental concern. 

"It's easy for you," he wants to say. She's an alpha. 

Though he's been with women outside of heat, he's the type of omega who cycles into heats that only attract male alphas, which spared them no small amount of awkwardness during adolescence. 

But he knows Raven's never been with someone. Even if he stays largely out of her head, he knows she fears it. Alphas lose control, too, during a mating. She'd have no way to be certain she'd keep any form besides her own. She's worried after his willful disregard of his body for years. Being an omega might seem more demeaning, he thinks, but it's unfair to think matters are any more simple for Raven. 

"Now's just not a good time for it," he says, instead, looking away at the complex. "We've work to do here, I can't--"

"You had 'work to do' in Oxford. For years. Charles, you're twenty-nine years old."

"I think I've somehow realized that myself," he jokes. He walks closer, and the soft undercurrent of worry from her mind is easy to block. "There's countless omegas who go their whole life, unmated." It feels more like he's reminding himself than he is Raven of the fact. 

"But to shut off a whole part of yourself, and for so long... Isn't it painful?" 

He winces, and almost tells her how excruciating it is--like an intolerable itch deep in your body, unreachable; something like locking yourself for a week in a furnace, knowing you could just open the door and walk out, away from the agony, any time--but it'd just upset her further, make her more determined to get him shacked up with some alpha. 

"Not entirely," he lies, "Anyway, it's not like I could mate with anyone here. I doubt it'd look good on anyone's CIA clearance, making a mate out of someone who can pick state secrets right out of your mind." 

"Erik doesn't even have a security clearance," Raven says, deadpan. 

"Why does everyone think Erik's my--" he trails off, catching her grin. 

"I know he's not. Not yet, at least," she adds, smug. 

"It's not that I don't want him to be," he says, honest to her in a way he's rarely honest to himself, "but he's not going to become my alpha." 

"Why not?" she asks. She's serious, he knows, and she goes on before he can respond. "He's interested in you. He's a little," she makes a gesture that somehow implies impulsive-and-hell-bent-on-revenge, "you know. But he's not the kind of alpha who just goes breeding anyone. He'd treat you well, Charles."

"Perhaps," Charles concedes, "for the next four days of heat, maybe. And after that? The man has his own agenda, Raven. He wouldn't stay around for anything past the obvious." 

Raven smiles again. It's a little rueful, a little sad, and Charles wants to touch her thoughts so badly. He's always tried to keep his promise to her, however, and he just attempts reading that strange expression as she replies. 

"I know none of us know much about him. But I think he wants what you want, Charles. You wouldn't last a week with an alpha who wasn't as driven as you." 

It could be the heat speaking, but it was true, he realizes. "You're saying I'm doomed to raise a litter on my own, because I couldn't cope with an alpha who'd try and keep me."

Raven laughs. "Now I know you need to get laid. You're not a dog, and I'd like to see you fat enough to handle twins," she jokes, pinching his arm playfully. He rubs his arm, faking grievous injury--the way he's done ever since she first pinched him as a kid--and she pushes off against the wall. 

"Well, I hope that little talk helped. Now, I'll leave you two alone," she says, giving a little wave.

It had better just be an expression, he thinks, turning with something not unlike dread. If Erik's behind him, it means three things: 

One, Erik walked clear around the complex to the other exit, ignoring the sensible option of following Raven out, and the motion seems illogical except in a mortifying evolutionary perspective: _watching my back_ , Charles thinks, _keeping me corralled between him and a family alpha, minimizing the threat of an outside mating._

Two, Charles's powers are deteriorating enough to be useless this year, and if he wants to keep himself relatively unmolested he had better lock himself in a room alone, and quick. 

And three... Oh god, worst of all, it means Erik has likely heard half the conversation. 

The last half.

He turns, and Erik's standing there, looking smug. His arms are crossed; it makes his shirt draw tight across the muscles of his chest, nothing to the imagination, and Charles starts to get wet. 

"Really," Erik says, moving--stalking--closer, "a litter?" 

"I'm tired of feeling like an animal," he says, and he's unsure if he's trying to explain himself or warn Erik off. 

"You are one," Erik replies. It's a blunt reply, the sort of thing he knows some alphas really think about omegas, sometimes, when they're crazed with heat, and Charles goes to draw back. Erik catches him with a broad hand, surprisingly gentle, around his wrist. "Eating, breathing, reproduction... In these ways, we are no different from animals. But you are so much more exquisite, Charles." 

He's leaning in, taken with Erik's scent, watching his mouth as he speaks, and it's no shock to him when Erik's brushing a hand possessive down his backside, when the words "So much more evolved," hot against his ear. 

It's cheesy, he tries to think. A terrible pick-up, the sort of thing _he'd_ try in some bar with a nice omega girl, and oh god, Erik's cock is huge where it's now pressing, hot, against Charles's stomach.

Erik could say anything now, he thinks, and Charles wouldn't care, just so long as he can get that thick cock up his ass. Just as long as he can get Erik mounting him, now, filling him with cum until he's choking on it. Charles feels feverish already, but he knows he's blushing when he makes a high, needy noise and begins grinding back against Erik's hand, feeling the slick leak slow from his ass. 

"Charles," Erik chokes out. His fingers curl once more up against the seam of Charles's pants-- _have I soaked my trousers_ , Charles thinks, desperate and horrified, _can he feel how pathetic I am, how much I need this?_ \--before he's pushing Charles away. 

Again, Charles makes a broken sound, and he fights Erik momentarily. Having given in even this small amount to his body, it's nearly impossible to come back to his senses. Erik's got a longer reach, he should be able to hold Charles back, but the show of strength only gets Charles more needy. He transmits everything to Erik, half-mad, a blur of base urges and images of him being pinned, used, kept coated and filled with Erik's ejaculate for days; of Erik fucking him months later, keeping him filled even when he's heavy with Erik's child.

There's a moan from Erik, a moment where Erik's pulling him back, his belt coming undone and his zipper being eased down without a touch, before Erik gasps, "Charles, stop." 

_Stop_ , Erik sends, the clearest telepathic message he's ever sent to Charles. There's images of walls, of doors closing, of ice water, and Charles reels back, stumbling. He kneels heavily on the grass, coming back around from being tossed from Erik's mind, from the damp chill of dew against his knees and hands. He can't really blame Erik for keeping his distance, for not trying to catch him. 

"I'm sorry," he pants out. "Sorry. God, I don't know what came over me."

Erik is no less shaken. "You're nearly two days in heat," he says. He's looking anywhere but at Charles, and Charles can feel the metal around them vibrating faintly. 

"But I shouldn't--

"You shouldn't be outside of your bed." 

If anything, it's meant to be humorous. But the words make Charles dizzy, again, and he's starting to lean forward on his hands, arcing his backside up before he's conscious of it. 

_Here, do it here, it can't wait, now--_

Erik takes a single step forward, his expression making Charles spread his knees further, mindless, before he stops again.

_No._

"Get off your knees," he says, roughly. "Before someone sees you like this." 

_Don't care, everyone knows we're mated, it doesn't matter, just please, Erik_ , Charles is begging, even if he's dimly aware he'll hate himself for this in four days.

"Precisely," Erik replies. Charles hadn't even been aware of sending the last part. He reads the continuation of the thought in Erik's mind-- _you'll never forgive yourself or me; impregnated outside, the animal you loathe being_ \--and he moans again, softly, this time with shame.

"I'm going to meet you in your room. Would you rather have Raven escort you, or--" 

Painstakingly, Charles is getting up off his hands, trying to stand. "I don't need an escort, Erik. I can manage."

"I'm sure you can," but the thought _he doesn't realize how heavily he's now leaking pheromones, surprised the entire complex isn't on him_ is sharp in Erik's mind. 

Even if she's fully aware he's in heat, the thought of having his own sister guide him to a room where he's going to be fucked for days is a little much. 

"Hank," he says eventually. "Get Hank." At least he knows Hank's going to be suffering this same embarrassment in the future. 

Erik nods and walks back in. It's like being woken from some spell, like sobering up. He finds he can stand, finds he's finally able to appreciate Erik's iron control. _I was going to let him. Out here_ , he thinks, appalled, _like a dog._

He feels nearly his normal self when Hank walks out, stammering nervously, and he realizes that Hank's not just there to keep him from attracting other alphas. 

He's there to keep him from fleeing the country. 

The walk to his room is awkward, certainly--not the least for when Erik's thought about pheromones is proven correct by Sean requiring Raven to rather forcibly pull him back to his seat--and Hank uses the opportunity to hypothesize at length about the implications of telepathy during pregnancy. Though he's still, in some ways, dreading this--the loss of control, the fact that after today he might be all too aware of the location of at least one new mutant and what that'll mean to him, to Erik--it's not soon enough that he's finally at the door to his room. 

Hank's trying to finish his point on prenatal education, and while it might be a little rude to do so (although it's not as if Charles hasn't had the last twenty-nine years to consider all the finer points of being a telepathic omega) mid-lecture, he gives Hank a quick "yes, thanks for the help," and closes the door. 

The walk had seemed to take ages, he's surprised Erik isn't here already. He's pleased, though, for the silence; for the chance to sit heavily on his mattress and try to center himself. 

This is still madness, he thinks. Still likely the worst time he could choose to mate, and yet--the way the world is, now, half gone to nuclear winter--he can't help thinking it may well be the last chance he gets. 

He finds himself hoping not, though. Not even one night with him, and he's already hoping for the impossible from Erik. He rubs his face, tiredly, annoyed once more with himself, and waits.

An uncomfortable stretch of time passes before Charles thinks, simultaneously, _should use the chance to get undressed, don't want to ruin this shirt_ and _he's not showing up_. He settles for optimism, and he's half-naked, shirt and shoes and socks in a heap, when the door unlocks from the outside with a soft click.

There's a bag slung over Erik's shoulder, a gallon of water in his right hand, and the reality of the situation sets in right then for Charles. 

He's not leaving this bed until heat is over, save for using the bathroom; he'll need Erik to grant him anything else, food, water, an hour's sleep. The thought would have disturbed him, once, but now--with Erik staring at him in obvious desire and _need_ , when he's re-exposed to the drug of Erik's pheromones--now, he's just getting harder from the feeling of belonging so completely to his mate. 

Pushing his trousers down roughly, he's completely bared himself before Erik even closes the door, and it'll be days before he'll have the mind to be thankful that no one walked by. 

Erik puts the water and his bag down, slowly, eyes never leaving Charles, and the door's closed and locked without him turning once. Swallowing, Charles hopes he's not going too far, not pressing Erik until he leaves, because if he doesn't get this soon he's going to burn up from it. 

"Erik," he breathes. "I--"

"Enough," Erik commands, sharply. Charles feels his balls tighten. "Get on your knees. I'm going to fuck you. Now. Just enough so we'll be able to talk."

Yes. Charles rolls eagerly on his front, goes to center himself on the bed facing the headboard, but Erik's large hands are hot on his thighs, tugging him back.

"Stop. I want you like this. Face the wall, back up a little--perfect." Even so little contact has Charles twitching, cock drooling precum on the soon-to-be-ruined sheets. He sends an inquisitive thought at Erik, a mental _anything you want yes why?_.

Erik readjusts him, roughly, and he hears Erik's belt snaking off his hips and Erik's pants unfastening. "This is easier on my knees. We're just calming your heat right now, Charles. I'll need the energy later, to mount you properly." 

The thought makes him cry out desperately--that there's a _distinction_ , that Erik's going to mount him for _breeding_ \--and the sound breaks off as Erik presses two long fingers deep in Charles's slick hole. 

He doesn't really need it, he thinks deliriously, he's open and he's felt that way for days, but Erik's fingers feel incredible. He thrusts back immediately.

Erik laughs. "Poor creature," he murmurs, hooking his fingers down against the heat-slick walls of Charles's ass. "So wet, so desperate. You don't even realize, do you--your boxers were soaked."

Charles gasps, rucks the sheets up in his hands and arches his back, offering himself. Erik's fingers move quicker, one more sliding in easy, an obscene wet noise filling the air as Erik works him open. _Please_ , he sends again, over and over: _please_.

"I was going to," Erik's saying. His voice is tight. "I would have done it there, Charles. You were leaking and ready, just begging for it out in the view of the entire CIA. Asking me to fill you like a dog--"

"Sorry," he chokes out, "Pressing you like that, sorry--"

"Not," Erik groans, sharply, as Charles tightens around him, "Not your fault, it's the heat, I--Charles, I want--"

" _Take_ it. God, just fuck me, wanted it days ago, just fuck-- _Erik_!"

He almost pitches forward, but Erik has him, hands bruising on the sharp arcs of his hips. The fat head of Erik's cock is pressing steady against him, and even in heat it feels too large for Charles to take. He's is tearing at the sheets, begging and cursing Erik, wild with pain and desire until finally, finally, it pops in and Erik sinks in deep.

Charles is still and quiet. Erik hisses through his teeth sharply as Charles tightens around him, but otherwise they're silent, Erik holding Charles steady as he breathes through it. 

_I didn't know_ , he thinks, unsure if he's broadcasting. _Incredible, that omegas do anything else, it's all too much, I need more--_

Even now he's still torn between wondering how he lasted so long without mating, and why he finally gave in. He's surrounded with Erik's scent, his body, and Erik's started running his palms firmly down Charles's trembling back and sides. 

"All right?" he questions, "You're shivering. Do you want me to--" 

"No," Charles says, as firm as he can manage while shaking and wrecked from finally getting an alpha on him. Erik keeps gentling him, waiting for Charles to continue. 

"It's just..." he trails off. It's impossible to describe, he realizes, particularly when he can feel every centimeter of Erik's cock tight up in him, when he can smell Erik's virility like a drug all around him, when he can sense concern and something like affection bright in Erik's mind. 

Charles has the feeling that--whatever it is Erik is experiencing right now, body tense behind him--it would be too much to send _everything_ he's feeling right now. He can't seem to get the words together, either, so he takes it all and pares it down, consolidates it into a burst of screened impressions: _never done this before, not in heat, don't know how I lived without_ and _stretched out and completely filled, but god you're huge, please don't pull out please_ and _need this so much, want to come, want you to come in me now, Erik._

Distantly, he feels Erik's hands clench on his hips and senses the spike of animal desire, but all he can do is keep projecting desperately until Erik does something, anything. _Need to come, god, please_ , he's sending when Erik finally, blessedly, moves. 

He can't even breathe for the sheer debilitating pleasure of it. Erik's hands are holding him steady, pulling him back in short jerks to meet the alpha's thrusts; the angle, the way Erik has him, he's helpless and open and feels speared apart. He wants to throw a hand down and touch himself, to reach back and grab at Erik's hand, but all he can do is grab at the sheets and make countless undignified little noises. 

"Good, I take it?" he hears Erik say. His voice is muffled by Charles's panting, by the rushing of blood in his ears. He squirms in response, trying to thrust himself back on Erik's cock. Erik just laughs and stills him, his hand squeezing at Charles's hip. 

Charles moans in mortification, but can't help trying again to fuck himself a little harder, a little faster. His thoughts are a mess of _what he must think of me, what's wrong with me_ , and somehow the shame of it only makes him harder. 

"Shh, no, Charles," Erik murmurs. Charles starts--was he projecting, will he be this out-of-control for the entire heat?--and Erik leans over him to kiss over his flushed shoulders. The gentleness of it is shocking. 

"You're beautiful like this," Erik continues. It seems unfair that he's so calm, still able to talk when Charles has been reduced to noises and half-formed thoughts. "Absolutely perfect, my Charles." _My mate_ , he's thinking, along with something not quite fully articulated even by his mind about Charles carrying his children, an instinctive wonder and adoration over the idea of it. 

He wants to reply, to say something to acknowledge what he's reading off of Erik. But the new position has Erik a little deeper up in him, and when he moves he's just _there_ , pushing against the heat-swollen complex of glands just up above his prostate. 

"Oh god, oh god, oh let me--" he babbles out suddenly. He's not sure how he's last this long, but that he's never felt before, not from anyone else and it'd always been so difficult to angle properly with the toys he could never properly remember buying. This is different, brilliant, and Erik fucks into him, working the glands again and again. The immediate need to come is overwhelming. 

Erik's hands are a little clumsy as he slides a hand down, a breathy "yes" ghosting over Charles's shoulders. Charles barely needs that, Erik's fist loose around his dripping erection. He shudders beneath Erik, his orgasm whipping through him almost before Erik's jerked him once. He's swearing, sobbing, and Erik's come-slick hand is working him through it; he wants to curse Erik for being so calm, but just as suddenly Erik's stilled above him, and yes, _yes_ \--

He can't help working Erik a little, squeezing around Erik's cock pulsing hot into him. It's too good, this soon after he's come, and a little painful, but he needs to do it in a way he's only half-aware is animal instinct. _I need it, Erik_ , he sends, _come in me, my love_ , and Erik's response is a choked-off noise and to push in deeper. It should be more uncomfortable, the way Erik's hand unconsciously tightens around Charles's spent prick, but all he can feel is Erik spilling deep up inside him. The moment stretches out, Erik heavy and panting over his back. He's a little delirious from it, wishing Erik'd just keep coming in him like this for hours, but soon enough it's becoming uncomfortable. His thighs are straining, his knees ache, his mouth dried out. He's not certain if Erik reads it off him, or if it's just that Erik's likely equally sore, but Erik's drawing out slowly. It sets off a new twinge of discomfort, Charles sucking in a breath as Erik pulls out. Erik sits heavily on the mattress beside him, stroking his back in wordless apology. 

He can still feel Erik's cum up in him. He wonders how long it'll take before Erik will have him pregnant. He wonders if it's happening right now. 

For the first time in days, he's not desperate to be fucked. 

He's not sure how long it'll last. Hours? Minutes? 

"Feeling better?" 

Erik's voice is still rough in that way to which he's slowly getting accustomed. He turns his head tiredly to look up at the alpha-- _his_ alpha--sitting beside him. 

"Quite," he replies. The answer surprises him. He feels like he should be more horrified by how he must look--ass still up in the air, come and slick leaking down his thighs--but instead his body is thrumming with a sweet undercurrent of contentment. Probably half of it is his hormones talking, but he can't bring himself to mind just yet. He grins back at Erik's smug smile, and gingerly moves off his knees to lay on his side, carefully avoiding the mess of come on the sheets. Erik massages lazily at his lower back. 

After bonding, Charles recalls tiredly, alphas often display a need for continuous physical contact until the omega is successfully impregnated. All the same, he stretches languidly under the massage. It feels heavenly. He's hesitant to interrupt the moment, and it's Erik who eventually serves as the voice of reason. 

"You'd best have some water, then," he says, drawing away with reluctance. Charles reaches a hand out to brush against his thigh, trying to maintain contact as Erik stands, and he sits up to lean against Erik when he returns and sits with his back against the headboard. He lets Erik hold the water for him and drinks gratefully. Perhaps he's never been bred during heat before, but there's some things that are instinct, as embarrassing as they may be. He's in heat, he thinks of telling Erik as he did Hank, not dying. But he knows Erik's as driven by biological imperatives right now as he, that an alpha's need to care for their omega through heat is as hard-wired as his need to be fucked. The thought sends another little wave of arousal through him. 

God, he thinks, it wouldn't be so soon. Would it? Erik's put the water back down and has gone back to idly massaging him. Charles can feel that he's already half-hard again, but there's no urgency to Erik's motions. Not for the first time, Charles wishes he had some experience with mating during heat. Erik, at least, seems somewhat better informed. 

"Have you--" he starts, uncertain of the protocol with such a question. "Er, during a heat, that is--"

Erik's mind goes distant. It's as clear an answer as his words. 

"I'm familiar with the phenomenon," is all he allows. There's darkness behind the words, and even if Erik's let down all his usual shielding, Charles knows better than to look.

He could kick himself. He's not ignorant, and anyone would know that with Erik's past--the shadows of things Charles has seen in Erik's mind, Shaw, the horrendous experimentation, the separation of countless mated pairs in the brutality of war and cruelty--the chances for a painless mating were few. Erik could have children already, he realizes, an omega who cared for him. They could all be dead, the children never allowed to be borne. Or Erik could have been made to do this, Charles realizes. The certainty is sickening.

Brushing his fingers over Erik's tense bicep in apology, he wants to undo the past for Erik. It's not the first time, and it won't be the last. You can't protect someone from what has already happened, he reminds himself.

But what he wouldn't give to do so. 

He wants to confirm Erik wants this, that it's not some terrible trick of Charles's pheromones--surely, his mind supplies traitorously, not all those CIA agents _actually_ desired him--but instead he asks Erik if he knows how long it will last, this temporary wave of sanity. He hopes the question will pull Erik from the dark mood, but he's still distant and contemplative as he answers. 

"It depends where you are in the cycle. For now, perhaps a few hours, unless you are stimulated before that time elapses. But as you progress, of course…" 

"Of course," he agrees. _Unless I am stimulated_ , his mind replays, over and over. Erik's still half-aroused, despite the course of the conversation. Are alphas always so during a heat? Should he offer himself now, would Erik be more comfortable, able to rest if he took Charles again? He's once more uncertain how to ask.

Four more days, give or take, he thinks. It seems impossible. 

"I'm sorry," he says, finally. He means, _for making you remember_ , or, _for inconveniencing you with this_ , or, _that you don't want me_. He's not sure if Erik picks any of it up, and he hopes not. Erik tenses again behind him and he quickly shifts to sit facing the man, blushing as the movement makes a little more cum trickle out of his stretched arse. 

"You must be, ah--" he trails off, staring openly at Erik's cock. It's thickening even as he watches, canting a little to the left. He bites his lower lip, trying to control the sudden impulse to suck him into full arousal. _Still coated in my slick, his come_ … 

Erik halts him with a hand to his chest. He can't even remember leaning forward, and he's coming to with his face nearly buried against Erik's crotch. 

"Oh, god. Sorry," he repeats. He's doing a lot of apologizing lately, and he's not sure if he's going to be able to stop anytime soon. 

He's still staring, unashamedly, at Erik's prick. His mouth is still flooded with saliva.

"You should rest," Erik's saying. It sounds half-hearted. Charles swallows, twice. 

"I imagine so," he says. He wonders how Erik's come tastes. Maybe he won't find out, maybe Erik will pull out and come in his ass, maybe shoot all over his face and chest, make sure all the alphas know--

By now, however, the idea's caught hold and Charles is almost unable to stop himself. There's still a part of his mind trying valiantly to hold on to rationality, a small part of him still thinking _scent-marking by a dominant alpha is advisable should an omega be required to be in public mid-heat_ , but mostly he just _wants_. He wants to suck the taste of himself off Erik's skin, to feel Erik hot against his tongue, to stretch his jaw and to gag over Erik's gloriously huge cock. 

This time when he leans forward, Erik does nothing to stop him. He's still tense, his surface thoughts warring between _need to protect my omega, stop him from pushing himself so early in heat_ and _yes finally, Charles's perfect mouth, those lips, he was made for this_. 

Both thoughts make Charles blush. He's just glad that Erik allows the latter to win out, that he cups a hand careful around the nape of Charles's neck and thinks _yes_.

Charles moans when he reads it. He's already close up against Erik's cock when he does, and he feels the lean muscles of Erik's thigh jump under his palm at the feeling of warm air ghosting over tight skin. It's almost as if there's a feedback loop between them, now, and it's not entirely from his telepathy. Charles is flushed, his hole clenching over and over like Erik was still thrusting deep up in him. He's just had one of the most exhausting orgasms of his life, and he's already getting wet again (more wet, he thinks, clenching again at the thought of how his ass is full of alpha seed). 

And it's because of this, Erik shifting beneath him. Reacting so _gorgeously_ just to a little sigh of air over his prick. 

"I thought you wanted to suck me," Erik says, the 'so get on with it' unspoken. 

_Obviously_ , Charles thinks, nuzzling blissfully at the join of Erik's thigh, just shy of that incredible cock. So perhaps it's a little teasing. He still can't help breathing Erik in, savoring the hot scent of sex and sweat and concentrated pheromones. He's lost in that smell. His whole world should be here. He should just live the rest of his days here, where he belongs, between Erik's thighs. 

Charles startles as if awoken when Erik's hand tightens sharply on him. 

"Don't tease an alpha during heat," Erik says. It's a warning omegas hear clear from childhood: alphas will go mad from their heat. But there's still little about Erik that isn't in control, his expression merely flustered. Charles smiles up at him, and slowly kisses over from the sharp curve of a hipbone, wondering again how much of the textbooks and classroom rumors are true. _Patience, darling_ , he sends, because having Erik squirm beneath him is lovely. 

And because he will never be able to get enough of this, he thinks as he mouths a wet trail inward. The catch of hair against his stubble, the heated press of skin, the wave of scent as a thigh turns outward, inviting. 

His hands wander over what he can reach, flank, thigh, abdomen, hip. When his touch meets the uneven edges of a crater left by some past brutality, or the raised tangling network of old incisions poorly healed, he doesn't pause. Erik's mind is constant, intent on one thing. That Erik tends to think of his body as a weapon, Charles knows. Though it's likely unconscious on Erik's part, Charles can only be humbled by how open he is at this moment, scars and all.

But eventually, Erik pulls impatiently at him with the hand on his nape. It's just enough for Charles to falter, and he's close enough to Erik's prick that it drags across his cheek as Erik thrusts up against him. 

"Charles," he says, voice low and urgent in a way that makes Charles pull away and look at him, "Please." 

There's something almost vulnerable in it, and hearing Erik beg isn't anything Charles had ever expected. 

_Anything_ , he sends, _my dear, anything_. He lets his hands rest on Erik's inner thighs, leans his head back down, and opens his mouth over the flushed glans of Erik's cock. 

While Charles has certainly had a reasonable amount of experience with oral sex, it's no preparation for this. Perhaps, the thought occurs to him as he sucks awkwardly and gags as he makes a clumsy attempt to take Erik too deep, that it would be helpful if that experience had, at any time, involved a penis. Maybe not, though. 

Erik's cock is enormous, and drool is leaking sloppy from where Charles's lips are stretched out, jaw held carefully open, constantly mindful of teeth. He swallows against Erik, again and again, uncertain and self-conscious. 

When he feels Erik's grip around his right wrist, he startles a little and pulls back, looking up. His lips feel slick, a little swollen.

"Believe me, it's not unpleasant," Erik says. It's almost a moan. Charles licks his lips again, emboldened. "I just think, perhaps you should--"

Erik trails off, as if shy. Releasing Charles's hand, he wiggles his fingers, the little parody they have of Charles's habitual mind-reading gesture. Obligingly, Charles looks.

It's not quite embarrassment that has Erik trailing off. It's a lack of words for it, an blinding wave of arousal that floors Charles when he sees it burning in Erik's mind. _Hand wrapped tight around the base, maybe pumping him a little, no need to choke unless--oh unless you_ like _it, you do, don't you, beautiful little cocksucker; licking broad-tongued over glans and all over, lapping off your juices, just do what you'd wanted to begin with; I want you, I want what you want, Charles, my…_

Charles pulls away from Erik's mind, gasping and overwhelmed, bucking his hips once to drag his cock rough against the sheets. Too much. Far too much. He's going to have to be careful with that during heat, crawling inside Erik's want and drowning in it, he's mad enough dealing with his own. 

_Beautiful little cocksucker_ , his mind replays, and he takes Erik's cock in his right hand and pumps him once, experimentally. 

God. How'd he ever think he could get all this down his throat? 

Burying his face back between Erik's legs he lets himself truly go with it. He forgets about trying to impress Erik, trying to get him deep, and just worships the scent and taste of his prick. He keeps jacking Erik with his hand, a slow twisting with his grip light--the way he usually teases himself when he's jerking off--and gives into the impulse to tongue Erik's heavy balls. They're drawn tight up against his body, and Erik makes a stilted noise when Charles's tongue works over them, when Charles opens his mouth and moans around the taut skin. 

There aren't any external physiological differences between omegas and alphas, Charles knows. But looking at Erik, he can't stop thinking the man was _made_ to breed him. He can't stop basking in the pheromones, can't stop obsessing over the sheer virility of this alpha-- _his_ alpha--how Erik's going to be filling and coating him and impregnating him. Groaning again, he licks up, along the firm underside of Erik's prick. 

He can still taste himself. Another trickle of slick runs down his inner thigh.

Erik strains against him again, urgently, when Charles laps firm and wet around the line of his circumcision scar. Charles is blissed-out, nearly high, and Erik has to moan with him when he sucks the glans back in his mouth, tasting Erik's precome. The tip of his tongue runs up the sensitive backside to dip firmly against the slit of Erik's cock, and Erik has to fight to keep himself from thrusting. Naturally, Charles does little to help, humming contentedly when Erik's steadily leaking. 

He already can take Erik a bit deeper, now, swallowing happily against the thick weight. But Erik's already reacting so wonderfully to this, to Charles sucking and licking just the glans, pumping Erik firmly with his hand. He shifts a little to steady himself better on his knees and elbows, freeing up his left hand to cradle and play with Erik's balls. 

This could last for hours, Charles thinks contentedly. He pulls back, letting the glans slip from his mouth to run his tongue down the side, trying to catch more of the taste of himself. He's been sucking wet kisses across Erik's skin, not caring about how he's still salivating over Erik's prick, and his face and hand and Erik's cock are slick with spit. He pumps his hand easily, now, a little tighter; and when he's going in to let the head of Erik's cock back in his mouth, Erik's cursing and grabbing at his shoulders. 

"Damn you, I need to--" and he breaks off in German. Charles can't find the power to reach for the translation. He doesn't really need it. 

Yes, he thinks, yes. He works Erik's cock, desperate for that first pulse of come, swallowing and bobbing his head and working his hand in tight strokes, panting, and _finally_. 

Erik groans and tenses, grip bruising, and Charles makes a muffled noise as Erik's cock twitches, as a burst of come overfills his mouth. Little matter, Erik's pulling him off with a curse, and the next pulses of semen catch him on his cheek, jaw, hair. Charles nearly passes out from arousal, from the sheer _rightness_ of this--his ass and throat filled with his alpha's ejaculate, being _marked_. He moans, weakly, not even caring what a mess he must look. 

It takes some time for Erik to stop panting. Later, Charles will have the mind to be proud of himself for reducing Erik to this. But for now he's still flushed and trembling between Erik's legs, working the last of the come out in gentle strokes until Erik winces and stops him. 

Charles is on the verge of another apology, a soft breathless "sorry," when Erik interrupts. His large hands are confident where they stroke over Charles's feverish skin, spreading the cooling ejaculate. 

"Perfect. You were meant to be like this," Erik says. His voice is musing, but Charles can't read him. His powers are useless right now, overwhelmed at once with waves of contentment and desire. 

"How could you deny this of yourself so long?" 

It's likely a rhetorical question, but all the same Charles answers, thoughtlessly. 

"You weren't there." 

The silence--and the halt in Erik's possessive massage--is just long enough for Charles to realize his mistake. 

He's a scientist, he should know better by now. 

This is just biology. 

Naturally, the silence is not long enough for him to draw away, for him to mutter excuses and flee. 

He's not lost his erection, either, and Erik simply says, "Come along, then," and pulls Charles up to lean over his chest, straddling his body. Charles thinks of running, even then. 

Erik's warm, though, one arm strong curved around Charles's back and his stubble catching rough on the curve of Charles's neck. His callused hand is already working at Charles's erection in firm, sure strokes. It's not meant to be drawn out, it's meant to be rough and quick. 

Charles thrusts into it, eagerly. Sooner it's over, he thinks, sooner I can run for it.

It's possible he's already pregnant, of course. That doesn't mean Erik would need to know. Resolutely, Charles thinks only of how logical it would be: he could go on with research, Erik could get on with revenge. Everyone wins. He ignores everything else: the way Erik's left hand is splayed gently over his shoulder blade, holding him close. The way, even when he's giving a rough handjob, Erik looks down constantly, seemingly fascinated by the feel of Charles's foreskin. The way Erik always just tucks his face back in to nuzzle at the join of shoulder and neck.

And he particularly ignores the way Erik's lips occasionally brush against his skin, tentative. Kissing him as if he's something ephemeral, something he needs and knows he can't have. 

Charles shivers, holding on to Erik tightly, helplessly. He should be pushing him away. 

It doesn't last long. It can't, Charles's cock too sensitive and the constant friction of Erik's grip too good. He's still a little dizzy from tasting and being marked by Erik and the occasional press of Erik's mouth. He ruts his hips desperately against Erik's grip, his gasps for air like sobbing. 

The orgasm is almost violent, Erik wrenching him close and making one final rough pass over the leaking head of Charles's cock, making Charles come over Erik's chest. Charles cries out, loudly--loud enough to alarm anyone walking by and to thoroughly annoy Raven, who has the adjacent room. Erik's mouth is on him immediately, brutal and intense, his cries muffled into moans by Erik's kiss. 

As intense as the orgasm is, he ejaculates weakly on Erik in two small spurts. He shudders again, slumping carelessly against the little pool of come. During heat, omega males produce little semen--which is, naturally, devoid of sperm cells--as the lubricating glands come out of dormancy, and Charles is surprised he is able to ejaculate twice at all. Orgasms, though... 

Well, there's always plenty of those, coming wetly around a dildo or, now--when he wakes up again, that is--around Erik's cock as he gets filled up, enjoying the benefits of an alpha's impressive hormonal response around a fertile omega. He mumbles happily, already dreaming of it, and lets Erik struggle and grumble to adjust them into a position somewhat conducive to sleep. 

It isn't until he's on the verge of unconsciousness, his head pillowed on Erik's chest, that he remembers his conviction to sneak away. By then, of course, it's impossible--Erik's got an arm wound possessively around him--and he's comfortable, besides. 

Logic can wait till morning.

 

He wakes. Disconcertingly, it takes him a moment to realize what exactly had roused him. He's completely at ease, he has an odd sensation that everything's right somehow in his world. Strangely, there's no thrum of urgency in his body, the only ache a pleasant stretch in his thighs. A warm weight is draped over his back, the smell familiar and welcome. 

A flush of heat runs through him, sweat prickling on his lower back. He's just discovered the reason he's so boneless and content, and he can't believe he only awoke _now_.

"Good morning," Erik says. There's a hint of a smile in his voice. 

Charles can't trust his voice just yet. He's still clenching wetly around the fingers crooked deep up in him, stroking gently now over the glands. 

"Yes," he agrees tiredly, the lassitude of orgasm and sleep heavy still in his limbs. Distantly, he remembers that there had been something he had been meaning to do this morning, but his mind is currently caught in a thick fog of contentment. 

And Erik still has not drawn his fingers out. Erik's sprawled out over his chest, and in that sprawl of lazy post-orgasmic contentment, Charles looks up at his mate. There's a surge of pride and want in Erik, just then--the word must have leaked over their connection. Charles reaches down, instinctively. His shields have always been particularly blurred first thing in the morning, and he can easily see how aroused Erik is, see himself as Erik sees him: used, absolutely beautiful, _his_. But Charles barely has his palm on Erik's prick when, inexplicably, Erik pulls away. 

He can't help the little noise of disappointment, embarrassing though it is, and the whimper is all too loud in the quiet morning air. The drive to please Erik is, at this point, hardwired. Being denied the chance to stroke Erik off, to take Erik's cock hot in his throat, is nearly painful. 

"Lovely as it would be, Charles," Erik says, "I believe we had other plans in mind." 

Erik's fingers twist again in him, sharply. The intent is obvious, and Charles feels himself flush with arousal and apprehension. " _To mount you properly_ ," Erik had said last night. The thought and everything it means--he'll be _properly_ Erik's, he'll be heavy with Erik's child--is terrifying. He pushes back desperate against Erik's hand and spreads his thighs. 

There's an answering flare of arousal in Erik's mind, naturally; but there's also surprise, as if Erik had been expecting refusal. As if I could, Charles thinks. His hand brushes up Erik's left arm, where Erik's bracing his weight above Charles, the relief of veins stark under his fingers. 

"Are you certain, my friend?" he asks, while he can. His voice is still rough, his breath still panting short and desperate, but Erik's fingers have stilled in him. He has to take advantage of any short spell of lucidity he can get.

If anything, this heat has taught him that the alpha behavioral texts he's read are largely erroneous, at least when it comes to Erik. But Charles has still seen enough mated pairs to know that Erik won't be entirely unaffected by this. It's easy enough to _imagine_ Erik resisting the hormonal drive to stay beside and protect a mated partner. All the same, he can't imagine Erik being anything else than resistant to the thought of a tie to this world unrelated to Shaw's death. 

Above him, Erik leans down; the movement shifts the fingers deep up in him slightly, and Charles whimpers despite himself. Erik's stubbled jaw rasps against his collarbone, and Charles wants to remind Erik that _smelling_ him isn't exactly answering the question. 

"I'll admit," Erik murmurs, "that this could have happened at a more convenient time. All the same, if I did not want to be here…" 

The thought is unfinished, as are many of those that seep through Charles's eroded shields. There are those that Charles agrees with: in a world on the verge of destruction, what does it matter, what better time than now? 

But there's also much he wishes to argue. Impressions of the child as the continuation of Erik's family, when he's certain to die avenging them; of Charles being able to raise this child into something powerful but wondrous, something so much better than the monster Erik envisions himself. 

And amidst it all, warm and stunning, the thought _were I to choose a mate of my own will, it would be you_.

There's little of this that Erik would share willingly. Charles responds only to the spoken thought, whispering over Erik's sweat-slick skin that, since Erik is so sure, then _please_ ; because it's hardly going to become a more convenient time any moment soon, and he breaks off in a choked noise when Erik apparently agrees to stop talking and get on with it, and hooks his fingers. 

Though he's apparently just come from this in his sleep, Charles is already leaking. He blushes as he feels a sudden gush of fluid slick Erik's hand. "Ah," he begins. He reaches down, absently curious about the state the sheets must be in, but Erik hums roughly and pins his legs up one-handed and works his fingers hard. Charles's hand falls back, useless, on his chest. 

He can't even thrust back against Erik's hand, the jolts of Erik's fingertips sending a shivering arousal through his body. It's all he can do to keep his eyes open as his head lolls back, to watch Erik's sharp features transformed with hunger. While he is hard, the the head of his cock rubbing sticky against his stomach as Erik keeps him pinned with his ass arcing up and as Erik thrusts in him, his orgasm involves that little. His cock twitches once, leaking a few drops. 

And Erik groans out that he's perfect, voice sounding wrecked, as Charles cries out and comes wetly over Erik's hand. 

A long moment passes. Charles can only gasp, shuddering, for air, mind blank. The world comes back slowly. Awareness of sweat cooling on his skin, of the firm weight of Erik's arm against him, of the sheets rucked up against his back. Of the residual twitch in his thighs, of the loose empty feeling left by Erik's fingers. And finally--as he's just starting to be able to form thoughts, most of which are centered around the fact he didn't even realize that was physically possible, and becoming half-sure it had to be a secondary mutation--he's acutely aware of the tension in Erik's body.

The arm across his legs is steady, but every line of Erik's lean body is strained. As much as Charles is tempted to try to right himself--at least push his hair off his forehead and close his thighs--it's not as if there's any point to doing so, now. Shifting beneath Erik's arm, he reaches out to put his hands on Erik's slim waist, and urges him forward. 

"No more hesitation, darling," he says; perhaps more candid than is wise, but what he'd just learned Erik can do with his fingers alone has left him a wrecked and unguarded. Erik smiles, once more all alpha smugness over the state in which he's left Charles. 

He's satisfied to note, though, that Erik's hands are shaking when he grabs a pillow and guides Charles into position. 

When he'd imagined being mounted by an alpha--a fantasy that was less rare than he'd ever care to admit--it was never like this. He's spread wide, wet and open, yes. But all the public imagery of heat is the same: an omega face-down, back arched, an alpha fucking down into them. Like cats in an alley. 

Certainly he's had sex face-to-face before. But that was with another omega. And--while he's not so naive to suppose that alpha-omega sex is entirely comprised of one position--there's a bit of a difference between sex and _breeding_. 

He's not quite able to disguise his uncertainty as Erik pushes another pillow up under his hips. Erik smirks. 

"Don't you trust me, Charles?" he asks, voice warm and teasing, and he urges Charles to clasp his knees and bend a little further. The strain in his thighs is delightful. "You never struck me as entirely the traditional type, but, if you like--"

Erik is thumbing gently at his swollen hole, and Charles all but whines. 

"No," he says quickly, and clears his throat when it comes out cracked. "No, this is just fine. Thank you."

As he moves to kneel between Charles's thighs, the head of Erik's cock rubs against Charles's sweat- and lube-slick ass. They both tense. "I meant later," Erik says roughly, "If this doesn't work…" 

"Even if it does, I would still appreciate the compari-- _oh dear god_." 

Charles can barely find the air to breathe. One minute, he'd been aching from the absence of Erik's cock pressing hot and urgent against his thigh, and the next Erik had guided himself unfailingly in. As loose as he is, the head of Erik's cock still feels huge, stretching him out. Erik's barely sunk in an inch, and Charles already feels full. His hands clench at Erik's lean hips. 

Braced over him, Erik just pants, and thinks loudly--loud enough it's a wonder to Charles that _everyone_ can't hear it-- _don't come don't come don't come_. Charles does his best to go lax, to not writhe against Erik's prick and get it in deep. Erik hisses, and reaches back. A flare of discontent rises up in the connection--Erik's just gripped the root of his own cock, tight and careless, trying to stop the immediate need to come.

His face is wonderfully flushed, Charles thinks. Now if he'd just--

"Charles, please," Erik groans. "If you want this to last, you're going to have to clear your mind." 

Right, Charles thinks hysterically. Shielding. Right. He cants his ass up a little more, thinking _right after he comes in me, then I'll be able to_ , but Erik holds him steady by the hips, sighing. 

"You have days left in your heat, Charles, please don't rush this." Erik would never admit it, but Charles can tell he's begging, voice low and urgent. Charles takes a steadying breath and tries to think about the ceiling, or the US government's odd appreciation for grey paint. He considers, very briefly, composing a lecture on Robertsonian translocations, but right now even the thought of genetics is painfully arousing.

Slowly--and the moment seems to stretch on for ages, Erik still and strained above him--he's able to calm himself. Erik relaxes. And, after another too-long wait, Erik lets himself sink in deep. 

Charles is so wet, he slides in easily. He's settled to the root in one smooth motion. The weight of Erik's body, as he drapes across him with a sigh, is lovely; Charles rubs at Erik's lower back and murmurs his appreciation, enjoying the sensation of being so full, so very surrounded and owned by an alpha male he's made half-mad with rut. 

The rumble of Erik's laugh only makes him more wet. Erik turns his head to kiss one of Charles's upstretched thighs. "I can still hear you, you do realize."

"Of course," he says, smiling up at Erik, brushing his hand over the sweat-damp hollows of his lower back. _So do be a dear and make me stop thinking, why don't you?_

And he does, far too easily. One sharp thrust, and Charles is already mad with pleasure. He can barely form a coherent thought about how outstanding it is to be fucked like this. Erik's right, this is… Well, he can't imagine anything being other than this. Watching his mate's face, the strain of his muscles, and--if he arches his neck up uncomfortably--he can even see the thick shaft of his alpha's cock, fucking down into him. 

Traditional mating be damned, Charles thinks, and he just tries to hold on. The angle Erik's at and the way Charles is bent nearly in two has Charles grunting helplessly with every thrust. He's so full, he can't take any more. He shivers every time Erik pushes in, Erik's prick shoving unrelenting up against his vulnerable glands. He's still tender and fucked-out from the fingering, and Erik's unrelenting pace soon has him squirming half in pain. 

He can't think of what it means, that he's whining and begging for more when Erik ignores his discomfort and just keeps _breeding_ him. Hyper-aware of every touch, each sensation, he feels swollen and--ridiculous, he thinks, it's not something that has a sensation-- _fertile_. There's no innervation in that part of the human body, of course, but Charles is so fixated on carrying this alpha's child he's half-certain he can feel the head of Erik's cock dragging against the small passage to his womb, hidden up past the complex of glands. 

Charles cries out as Erik pushes a little more at his legs, gets his prick in deeper than before. His only conscious thought is _in so deep, no way he's not right up against there, going to come right up against it_ before he's thoughtless and wild, clawing at Erik's ass. He's aching for it, for this--Erik's huge alpha cock up so tight in him he's almost choking, Erik's seed spilling hot against the opening. 

The storm of Erik's thoughts makes no more sense as it washes over him, all feelings of wonder and painful hope and vicious possession, and there's some instinctive, immediately discarded thought about _fuck him like this every heat, keep him this way_ that makes Charles buck under Erik's weight. 

Wet noises intermingle with the sound of their panting, and Charles feels another trickle of his slick start trailing down from his ass. He's nowhere near orgasm, but the need in him is almost agonizing. There's not a word for it, the old cultural bias against omega sexuality being what it is, but he's read about this plenty--the animal desire to be successfully bred during heat, a painful ache only alleviated by time or mating. 

Erik's thrusts are increasingly sloppy and careless, his eyes dark and fixated, now, on a point just above Charles's shoulder--a moment before, Charles had felt a spark of _too much too much_ from him when he'd been watching Charles biting his lips bruisingly.

_He's going to come in me_ , Charles thinks. He would have thought the idea of getting knocked up might be a little more sobering, but he just starts squeezing around Erik's cock, trying to milk it from him. Erik hisses in discomfort, and does nothing to stop him, nothing to pull away. He just winces and keeps pumping into his mate. For a moment, Charles feels like Erik's swelling in him. Like his cock is becoming monstrously wide, too large to pull out, like they really were just dogs. He sobs a little, thinking he can't take any more surprises about heat and basic human physiology at this point. Erik's hands stroke firmly over his thighs, up his sides, over his chest. It's assured and possessive, and it calms Charles immediately. 

"Hush, Charles," Erik mumbles. His voice sounds broken. Erik looks as if he's meant to go on and say something more, but can't. He thrusts, again and again. He's lacking the coordination now to even pull out more than an inch or so, and it's more like he's just shoving helplessly against Charles, moving as if he's trying to crawl right into him. The groan he makes when he comes is low and animal. 

The feeling of Erik's cock twitching in him, the pulses of come filling him impossibly further, makes Charles cry out again. It's not painful, it's simply too intense; he's helpless before it. He's being filled up. He's mated, he thinks, moaning again at the very idea. Erik's balls are pressed snug against his arse, and Charles keeps thinking _how much can he even come in one go, this isn't human_ as the little jerks of Erik's cock and the hot rush of semen goes on and on. Erik's pressed as deep in as he can go, and the knowledge that so much ejaculate is spilling right up against his womb makes Charles even more wet and eager. There's no way, he's certain, that he's not getting pregnant from this. 

Erik comes into him, for what seems like ages. An alpha in full mating rut, Charles read once, can have orgasms that last upwards of sixty seconds; the average ejaculatory volume a full thirty to sixty milliliters.

It feels impossibly longer; impossibly _more_. He can feel when Erik stops contracting in him, but he stays in, balls-deep, after the fact. _Keeping the sperm in_ , Charles thinks deliriously. 

It's shocking, how much he appreciates it. He nearly purrs when Erik starts brushing kisses over whatever skin he can reach as he softens. Despite the fact he's not yet come himself, Charles's limbs feel warm and heavy. 

Sighing with drowsy contentment, he guides one of Erik's hands to rest low on his stomach. There's only a soft rise there, now--he's not at all embarrassed about it, he assures himself, bit of academia and beer never hurt anyone. All the same, Erik rumbles against him, and Charles blushes as his adoration and pride suffuses the room.

Erik remains in him for some time, after, only withdrawing when his cock has softened enough that it's no option. He stays draped heavy over Charles's body, a soothing weight, and Charles manages to suppress the urge to whimper at the loss. Slowly, Erik kisses him; rubs gentle circles over the nonexistent swell of Charles's stomach. Lying under Erik like this, warm and basking in Erik's affection, Charles can almost convince himself that this mating was a good idea. Erik nips lightly at the sensitive join of neck and shoulder, making Charles shiver. He can very nearly believe that the whole illogical biology of mating is quite possibly the best happy evolutionary accident ever to befall humanity. 

It's only when Charles's legs begin truly burning with the strain of being kept upright that Erik pulls reluctantly away. Before he can apologize for letting the pain leak through to Erik--he's given up hope of forming a decent psychic barrier, at this point--Erik is saying, "Really, Charles, you must stop apologizing for your nature." 

"I… Well, all the same," Charles begins. He's not quite certain how to continue, how to explain _nature or not, I should be able to control myself_. Luckily, he'd tried to let his legs down in the moment--let up a little of that tension in his hips--and Erik wound up interrupting again. 

The way Erik stopped him, holding his legs up again, it was obviously thoughtless animal instinct. 

"Stay. Keep it in," he growls before seeming to come back to himself. He flushes, pulling his hand away as if scalded. 

"Charles, I don't--" 

Laughing, Charles lets his legs slide slowly down. He ignores the shivering sensation of Erik's cum trickling from his ass, and--feeling oddly reassured, knowing he isn't the only one failing at hiding and at embracing basic biology--he lazily tugs Erik back. "Don't worry," he says with all the smug certainty of an omega well-assured in his ownership over a mate, "if it didn't take, I'm quite sure you'll find a chance to make up for it."

Erik lets himself be pulled back over Charles's chest. His grin is all teeth. 

"At the least," he says, "I know I can be sure you won't mind the attempt."

From there, the next days go on much as Erik had predicted, before. 

_It depends where you are in the cycle_ , Charles remembered. _For now, perhaps a few hours, unless you are stimulated before that time elapses. But as you progress, of course…_

The gradual abating of desperation that he's used to with heat--at some point in his prior heats, it would always seem as if his body would (much like his mind) give up on the hope of Charles ever successfully finding a mate--is nowhere to be found this year. Erik is nothing if not vigilant in his attempts to ensure Charles doesn't faint from lack of food, but it's difficult. 

"Please, Erik," Charles will tease, "you know I'm not starving for _that_ ," and he'll try and lunge for Erik's cock again. He begins fighting sleep, water, the stretches of time when he's just come violently and Erik insists he rest. Somewhere around the fourth day of heat, he's lost all concept of time. He's lost the concept of anything aside from the need to have his alpha in him.

For the first days, Erik continued to prove those decades of alpha/omega sexuality lessons wrong. He'd mate with Charles in any position, some of which Charles felt were frankly impractical for the sake of impregnation. Lifting Charles up against the wall, fucking up into his dripping ass as Charles howled and scratched his shoulders; or pulling him over to straddle the alpha's hips, encouraging him lewdly as Charles ground himself in a rhythmless frenzy on Erik's thick cock. Sometimes, right after he'd ejaculated, when Charles had already been moaning with that peculiar sated feeling unique to being bred, Erik would roll him on his stomach. Charles would feel Erik kissing over his shoulders, or down his back, and--unexpectedly, every time--Erik's fingers in his ass, heedless of the thick wet mess of come, working him to orgasm; or Erik's mouth on his tender come-slick hole.

Once, still writhing from orgasm--one that had even coaxed a few weak trickles from his half-hard cock, Erik's callused fingers had been so thorough and relentless--he'd managed to question it. 

"Why," he panted out, curling around himself exhaustedly, "I-- not as if I don't--" 

"I should say not," Erik had said roughly. His fingers dragged back and forth, sticky with come, over the slope of Charles's hip. Charles had waited for Erik to continue, but when it had become abundantly clear that Erik was only interested in nuzzling at him lazily, he tried to finish his thought. 

"Truly, Erik, it's lovely, but I don't see the, ah… evolutionary purpose." 

It hadn't been quite what he'd meant to say. He had blushed when Erik just pressed closer and chuckled lowly. "You Americans really are as puritanical as I've heard," he'd teased; and before Charles could become affronted Erik turned him back to his stomach, began kissing down his spine. "It seems to me there's every evolutionary advantage, Charles." 

"How many cycles would you allow me to breed you through," he had asked, making Charles shiver as much from the words as the hot caress of breath over skin, "if I always have you like this?" 

As if in emphasis, Erik's bristly jaw had scratched against him; his tongue had dragged wet and lewd over his tailbone. Oversensitized, Charles had batted him away, laughing.

Much later, Erik would also admit--voice low, perhaps even shy--that he might be wrong, not having read about it as Charles clearly had, but that he had always been told that making an omega orgasm during heat would ensure a successful impregnation. Charles would kiss him, lingeringly, and whisper a foolish promise that there would be more cycles, that they would prove that hypothesis yet. 

It was the sort of thing he had a mind to say at that point of his heat. By day four, however--

Charles would sometimes allow Erik's fingers or tongue, post-mounting. He'd allow the occasional coax to the bottle of water. 

He wouldn't entirely fight off Erik's attempts at holding him down to ensure he'd take at least a second of rest before begging feverishly for another breeding. 

But eating had become out of the question. And, increasingly, so did anything else besides the simple animal drive to be mounted. Erik would sometimes try and roll Charles on his back, or curl easy around him from the side, but as heat wore on the patience for that treatment left Charles. 

There was, Charles would realize once his mind had come back after the completion of his cycle, a very real reason for all the classical portrayals of heat-driven mating; for the way the lurid heat porn he'd jerk off to during his last cycles inevitably used only one position.

Like countless omegas before him, Charles would ultimately spend the last days of heat on his stomach, his lower spine arched. 

Displaying himself, keeping himself ready for breeding. There's countless slang names for it, most of them vaguely derogatory to omegas. As a scientist, however, Charles can only think of it as it's put in literature: _lordosis behavior_. 

It was a hard-wired drive to stay like that. In a way that was not at all conscious, Charles keenly needed it; needed to keep the head of Erik's leaking cock tight up his ass and pressed as deep as possible. The comparison of an omega in heat to a mere animal was unfair (particularly when the same comparison was rarely made with alphas, who were just as obviously affected by the unrelenting drive of biology), but it wasn't entirely without justification. 

Erik was trying to guide him on his side after another mating. It had been short and rough. The time Charles was now allowing for rest was short enough that Erik never entirely recuperated. He'd already be dripping with sweat and wincing from overstimulation as he'd mount Charles's upturned ass, but Erik was so deep in rut he'd come in no time regardless. 

Charles's thighs and the sheets were slick with ejaculate.

"Please," Erik coaxed, pulling at Charles's sweaty hip, "Charles, you have to rest." His voice was half-broken with dehydration.

Though he'd just been happily projecting contentment--the one of the few things he was still able to broadcast, his telepathy limited to increasingly short bursts in the moments immediately after Erik came--Charles all but growled his disapproval. 

_No_ , he sent. He knew better than to attempt speaking, his own throat raw from shouting and begging. _No. Breed me_. He arched his back and splayed his thighs further, as if in command. He no longer particularly cared what was physiologically possible for Erik. 

He just knew he needed thick alpha cock in him continuously. 

"Fuck," Erik groaned. His hand faltered on Charles's side before he began pulling with more force, careless and rough. "I can't. You _know_ I can't. Please, Charles, you need to--"

One of the unfortunate facts of heat was that the hormonal drive that made logical thought so impossible rarely prevented you from remembering everything later. Erik did get Charles down on his side, letting up the strain in his shaking legs and cramping back. 

It felt wonderful. Charles had been completely exhausted, his legs on the verge of buckling. All the same, it only lasted a minute before Charles attempted to right himself, to get back in position. And when Erik pressed him back, using his strength to keep Charles down until he was ready to mount, Charles struck out.

He scratched, kicked, tried to bite at Erik's arm. Anything at all he could do to force Erik to let him go, as painful as it might be for him or Erik, it didn't matter--he just needed mounting, more than anything else. It would have been horrifying enough to have that memory of fighting Erik, of harming this brilliant man who'd already been wounded all too many times. But when Erik continued--in the instinctive way of an alpha determined only to keep a heat-mad omega from injury, regardless of any risk to himself--to placidly hold Charles down despite the attack, Charles sent _breed me, damn you. Breed me, if you're too weak, get me another goddamn alpha and let_ him _mount me._

Once the heat had passed, Erik would try endlessly to convince him that it was understandable. That Erik knew he didn't mean it, that Charles couldn't hold himself completely accountable for the things said during the madness of heat. That all was forgiven, that omegas always struggle with the need for successful completion during the last hours of heat. Charles would never be entirely reassured.

But in the moment, Charles was only viciously pleased that it worked. 

The need to scent-mark, the instinct to lock an omega up until heat is completed--all the traditional possessive alpha habits lead up to this, to the moment where an omega is so crazed with the drive for impregnation that they'll do anything for it. And, as atypical as Erik might have been when compared to the alphas Charles had read about, every possessive instinct was still present in him.

And they were all, Charles was happy to find, triggered by that threat. 

Where he'd been holding Charles down, Erik suddenly and bruisingly wrenched him back up, all but throwing him back in position. 

"No one else," Erik was growling, the words nearly lost under Charles's lewd begging, "No one else could handle you." 

It would seem like typical alpha bravado but--Charles whined in pain as Erik carelessly plunged in, scratched desperate at the sheets and sobbed in need--he couldn't help thinking Erik was right. It was difficult to imagine some nameless undergrad, or some CIA suit, able to give him this; able to make him scream and yowl like an animal mere minutes after having just filled him with seed. 

He could feel his hips bruising already. The thought that he was going to be marked, a purpled imprint of Erik's fingers fading slow into green and brown, made him even more crazed. 

Fucked as raw as he was, there was little left of the usual pleasure of sex. He didn't care about technique, about the way Erik had learned to undo him easy with a mouth slack and hot around his prick and gentle pressure against his perineum. 

If he wasn't in heat, he would have stopped hours ago.

When Erik came in him again, he sighed. _This time_ , he always thought. _Now I can rest, this is it._

_This will be over soon_ , he always had to promise himself after Erik shot deep and Charles still itched with uncontrollable need. 

And sometimes he knew Erik had heard him from the gentle rub over his lower back, slow and soothing, like an apology in the midst of their shared madness.

For the entire duration of his first heat, Charles had been certain the condition had to be fatal. Surviving a week solely on adrenaline was just physiologically impossible. 

Then--and in every heat since--the sensation of completion would be nothing else than sheer, pure relief. It was like surfacing for air, like the breaking of a fever.

As enjoyable as it is, even compared to his previous heats, these days--long and humid and heavy with the scent of Erik's pheromones surrounding him--seem endless. Charles begins once more to think, in his few lucid moments, that heat must be deadly. 

There's no way any human could survive this. 

At some point, he manages to glance at his long-ago discarded watch. Haphazardly tossed on the floor by the bed, it'd fallen in a position where it's easy enough to read if you're sprawled out over your front for hours at a stretch. It's either three in the afternoon on his fourth day, or three in the morning on his fifth. He's not sure how long he's been without food, and it's easily been as long without sleep. 

And Erik's just beginning to mount him again. 

He grunts in pain and satisfaction both, pushing his hips back in a weak stuttering rhythm to meet Erik's thrusts. Erik's arms are crossed around him tight, hands pressed against his chest to support him when his muscles give out. It's just like the mounting before, like the last several before that--some time after Charles began fighting and cursing him, Erik had stopped his attempts to keep Charles from fainting of exhaustion. If he does collapse after a mating, if he does sleep for a few minutes, Charles can tell Erik's glad for the reprieve.

Otherwise, Erik just seems to do his all to keep up with Charles, best as he's able. His hands slip constantly on Charles's sweat-soaked skin, his thrusts are reduced to mere animal rutting. 

Charles wonders if Erik feels the same. Is he half-certain he'll die here, from the exhaustion of coupling with a heat-ridden omega? Is he regretting this even now, Charles would ask himself, that he's never going to exact his revenge--that he's about to be killed, instead, by the strain of mating?

The sheets are bunched roughly under his face. He's sticky, uncomfortable, fevered. He wants Erik, still; over and over, constantly. He needs this, he's endlessly needing this one more mounting, this one last attempt at breeding. 

And then something shifts.

Erik's growling in rut, the jerks of his hips short and thoughtless, just like the mating before. Charles is whining desperately with the urgent need to be filled, as he nearly always is now. 

And, without warning, the thrusts are too much; they've become intolerable. 

Unthinkably, he begins fighting again--this time to get Erik off his back. It's as if something instinctive in him has been triggered. 

At first, Erik seems to brush it off. He grunts impatiently and tries to pin Charles, fucking him heedless of the struggle or the blunt scratch of Charles's nails. 

He needs to come now, Charles thinks. Erik needs to come in him now, or--Charles cries out, twisting in Erik's grasp. Behind him, he can feel the first shaking tremor of Erik descending into orgasm.

It should be enough. He should be able to wait the minute it'd take before he would be basking in that rush of short-lived completion, of Erik thickening and filling him once more with cum. 

Instead, with a strength that startles him as much as it does Erik, he manages to haul himself around and bite Erik. 

Hard. 

He's aware of Erik's grunt of pain, of the shock of blood in his mouth, but he only cares that Erik's stunned enough to drop him from the tight clench of late-heat mating. Charles hisses, a breathless noise, at the sudden wrench of Erik's cock pulling out. 

Every part of him is aching, but particularly there: he's been fingered and fucked to senselessness for days, the trickle of Erik's cum leaking out of his loose hole a now-familiar sensation. He manages to turn himself, sitting back on his haunches, getting the sheets stained again in the process. 

Heart racing with adrenaline and the thrill of besting an alpha, here--of throwing off this alpha during a mating--he faces Erik. 

It's only then, trembling and bloodied, that he realizes he has absolutely no idea what just happened. 

If it'd been his instincts that had made him think it would be a relief, not having Erik's cock huge and leaking in him--well, so much for instincts. He feels feverish, half-certain he's lost his mind. 

Ass clenching against the nearly-agonizing sensation of being empty, Charles can't find his voice. He thinks he's just able to send an impression of _sorry what is the matter with me sorry_ along with the pathetic little whine that comes from his throat. 

As mindless as he is, he has no idea what to expect of Erik in response. He's just bit the man hard enough to draw blood, the imprint of his teeth purpling on Erik's shoulder. He shivers again, all penned energy and no idea where to go with it. Aren't alphas, he thinks as he makes another helpless little noise, supposed to be the violent ones--

When Erik lunges at him, pinning him easily on his back, he isn't exactly surprised. His breath comes out in a startled grunt, and his hands come up instinctively, the return of that strange vicious urge to fight a shock. 

" _No_ ," Erik commands. He is easily the better fighter--particularly now when Charles has hardly any powers on his side and even less control over the more complicated world of tactical hand-to-hand combat--and he's heavy and unyielding against Charles's struggles.

Moaning, Charles shamelessly thrusts his growing erection--it's the hardest he's been in days--against the restraining weight of Erik's body. 

Whatever it is that Erik mutters, Charles has long lost any ability to translate. Erik pins him more tightly, and Charles fights him harder for that brilliantly rough pleasure of rutting his cock low against Erik's stomach; and he could go on doing easily, go on struggling till he shot whatever pitiful amount of come he'd be capable of producing this late-heat against Erik's skin. And suddenly it was the only thing that mattered, the fight getting him off as much as the friction. Erik kept speaking to him, urgent-sounding, low, and as indecipherable to Charles in English as it would have been in French or Polish or German, and Erik kept pinning him tighter. And he was desperately, painfully close to orgasm, and he didn't care how many days this fever lasted as long as he could have this, always, and Erik's hand is suddenly off his wrist and Charles can get a hand down between them for all of two furtive and glorious strokes before Erik slaps him.

"Charles," Erik is repeating for a countless time. Charles comes around, as much from the shock of Erik's continued determination as from the slap itself. 

"Y-yes," he's just able to say. "Um." He swallows. 

It's impossible to focus. 

He feels drugged. 

"Good," he thinks he hears Erik say, under his breath. "Hello, again." 

For all Erik's grip is still tight, the words are affectionate; even teasing. Charles swallows, is able to make out a hesitant "hello," in return. He's still not really sure what just occurred, and is that blood--

"Charles. Stay with me. I need--" Erik trails off, looking uncommonly nervous. "You need to decide, I know it's difficult. Do you want to prolong--" 

He's trailed off again. The thought of prolonging heat is exhausting, and at first Charles loudly wonders why Erik would even ask that. Erik's responding thoughts are noticeably blank, but there's a deeper riot of emotion, and the meaning is clear enough.

That this may be over soon--the words _successful completion_ float through his mind. He grips Erik's hips, hands shaking, and tugs at him impatiently; and yes it might be completely irresponsible to make a decision about becoming a father at this stage but all he can think is _yes_ and _god, now_. Erik's muscles are tense, shaking under Charles's touch. 

"Good," Erik says. Charles groans lowly at the stretch of Erik's cock pushing back in, a slow steady press. It feels uncontrollably pleasant, the itch to move back on his hands and knees easily ignored. And for a few short jerks of Erik's hips, it's perfect: what could be better than this, than laying back under the intense attention of an alpha like Erik? He lets his hips go slack, one leg curved loose around Erik's back, toes curled. He grunts, softly, with each thrust.

Soon enough, though, that strange feeling of _need to get him off me, now_ comes over Charles again. For some unthinkable reason he begins to struggle again, to fight Erik as he attempts to fuck him to completion. 

"Sorry for this," he hears Erik mutter under his breath, and at first Charles still doesn't understand; he's only struggling lightly, now, just for the pleasure of rubbing himself off. But as the odd agonizing tension mounts, he kicks and tries to attack Erik more fiercely, and the clench of Erik's hands around his wrists becomes bruising. 

It's not clear why he's fighting, but it's clear, now--whatever he attempts to do--Erik's going to finish this. He's pinning Charles down, heedless of how Charles yells; he's ignoring the strike of a foot or the sharp pain of being bitten. Charles curses him, cries out; anything to stop that sensation of Erik thickening uncomfortably in him, of getting ready to shoot deep. 

This madness is unlike anything he's felt. It's as if he instinctively wants this to go on forever--to keep fighting Erik down, just to that point where he winces and pulls out, to keep Erik always at just this point, fucking him this constantly and brutally for years. But it's impossible, now, to get any purchase on Erik; as much as he fights, it's hopeless. 

Though it doesn't take long--he'd been on edge when Charles had first forced him off--when Erik finally comes, Charles has been reduced to merely shivering and snapping at Erik ineffectively. The noise he makes is embarrassingly like a sob, breathy and pained, and his hips cant up as Erik thickens and pulses heavy inside him. 

There's a long moment where the only noise is of breathing, where his mind is perfectly and peacefully blank. He becomes aware of his surroundings again, slowly; but he's still centered on the warmth of Erik's breath against his neck, of where Erik's still half-hard in him. When he finally has the energy to tilt his head a little and kiss Erik, it's sloppy and uncoordinated, and he smiles lazily when he feels Erik laugh. 

"I had," Charles says, wishing his voice didn't come out sounding quite so awestruck, " _no_ idea."

"Hmm. I noticed." 

Charles winces. "Yes, well--"

"Though I suppose I ought to watch my words," Erik says, and when he stretches a little it's not without a wince of his own. 

"Oh god, you're-- I _bit_ you," Charles realizes again, and he drew blood. He attempts to sit up under Erik.

He lays still immediately, blushing. Erik's still heavy on him and--more importantly--in him. "God, I'm sorry," he says in a rush.

Erik seems, at most, entertained by the very idea of having been attacked--Charles was now studiously not looking at all the places he'd managed to bruise his mate--and he readily agrees. "Yes, you bit me. Several times." 

"You speak as if _mauling_ you was perfectly ordinary behavior." At this stage, there's no particular reason to hide his incredulity over the reality of heat. He's sore and sticky and ready to eat a twenty-course dinner and pass out for a month, but an answer or two might be nice beforehand. "You can't tell me that omegas are all going about doing… _that_ ," he finishes, awkwardly. 

The whole situation is more than vaguely unnerving, and he'd have a better chance of being offended if Erik weren't so smug. 

"Perhaps not all omegas," Erik allows. He kisses Charles's neck, light and careless. By now he's softened to the point where he has to pull out, and he does so gently. The twinge of discomfort is, in it's own way, satisfying. It's the sort of feeling that makes him think he can very well do without sex for a few weeks. 

"You see," he begins. "It felt biologically instinctive, but that can't right. Perhaps it's correlated to my mutation, as there's nothing in the literature regarding omega aggression during heat."

"It's not uncommon. How complete is your literature, I wonder. I don't suppose you have entire texts on fellatio--" 

"Erik, fellatio isn't _instinctive_." 

Erik grins, and Charles flushes once more. He doesn't say anything, but the thought _it was for you, wasn't it?_ is obvious enough. 

"Believe what you like," Erik continues eventually, "but if it's enjoyable, wouldn't the instinct be to stay in heat?" 

Charles's first thought is to say that it _wasn't_ enjoyable, but it wouldn't exactly be the truth. Erik's thoughts are somewhat closed, and Charles is as wary to pry as ever. Charles has never been particularly inclined to make sense of the muddled images left by someone's memory of heat, so his mind shies easily from those corners of Erik's mind. But it's impossible not to read a few surface thoughts from Erik in that moment. Erik's never experienced it himself, but he's heard stories, he's seen enough alphas bearing bruises proudly; the embarrassment of a child learning about heat, his alpha aunt saying _you take care, your mother broke your father's arm, you know_ \--

He pulls his mind away, flushing when he catches another stray thought--something primal and subconscious in Erik, about a good fight meaning Charles will bear strong children. Seemingly oblivious, Erik is tracing absentminded designs over Charles's back. Thank god, Charles thinks, still blushing. 

At the end of all his other heats, he'd get up and tend to his other basic needs before passing out. He would never consider sleeping without washing off all the sweat and cum, and that's when it was just him. He wants to bathe now, of course--he's sticky and quite certain he smells atrocious. But he wants nothing more badly than to just lay here a little longer, warm and content with his alpha. He forgets everything else as Erik turns him gently and begins massaging out the tension of days in breeding position, and starts dozing pleasantly, surrounded by the scent of his first decent heat.


End file.
